Mortar shell



Sept. 26, 1967 R. J. SHERWOOD MORTAR SHELL Filed Nov. 10, 1965 INVENTOR.

v14 I M ATTORNEYS United States Patent 3,343,488 MORTAR SHELL Robert J. Sherwood, Hamburg, N.J., assignor to the United States of America as represented by the Secretary of the Army Filed Nov. 10, 1965, Ser. No. 507,259 2 Claims. (Cl. 10249.1)

ABSTRACT OF THE DISCLOSURE A reusable, similated mortar training shell having a positive means for locating the shell upon impact. An ignition cartridge is insertible into the fin or tail section of the shell which has appropriate openings to release internally generated smoke developed upon impact due to a smoke generating cartridge arrangement being slidably mounted relative to a firing pin assembly within the shell fin or tail section.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The invention relates to a mortar shell, and particularly to a mortar shell for use in training.

An object of the present invention is to provide a mortar training shell which encompasses the external physical, weight, and center of gravity characteristics of a live combat shell.

Another object of the present invention is to provide a mortar training shell of the above type, which is reusable, merely requiring simple and easy preparation for reuse.

A further object of the present invention is to provide a mortar training shell of the above type which is readily observable immediately after impact with the earths surface.

Still another object of the present invention is to provide a mortar training shell of the above type wherein a tail section is modified to receive a smoke generating cartridge adapted to fire upon impact of the training shell with the earths surface, thereby releasing a readily observable cloud of smoke.

Further objects of the present invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the structure possessing the construction combination of elements and arrangement of parts, which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIG. 1 is a view in elevation and partly in crosssection of a mortar shell for use in training, embodying the present invention;

FIG. 2 is an enlarged view in elevation and partly in cross-section of an element of the shell of FIG. 1 clearly showing all the parts thereof.

When training a soldier in the use of a weapon system it is desirable that an actual combat system, or one closely simulating the actual, be used. Furthermore it is highly desirable that the training system be reusable. This invention provides these criteria in a mortar weapon system. Moreover, this invention provides simple, easy and quick means of reusing the training shell, while affording a positive means of locating the shell after impact with the earths surface. Heretofore mortar training shells were, at best, complex structures having many external modi- "ice fications which tended to detract from the actual physical appearance of a live combat mortar shell. Psychologically, this was adverse to the training mission which, among other things, is to minimize the sensory hiatus between the training exercise and live combat conditions. By being subjected to these heretofore cumbersome mortar devices, a trainee could not avoid feeling that he was handling an article tantamount to a toy. As I indicated I avoid this defect, since I provide a mortar shell indistinguishable from the real thing. I have simply modified an actual fin or tail section to provide for a propelling cartridge and a smoke generator assembly, including a smoke generator cartridge and a firing pin therefor. The assembly is adapted to fire the smoke cartridge upon impact of the shell with the earth. The fire section is easily removed from the shell body. The cartridges may be quickly replaced for reuse of the shell. The explosive is replaced by a properly designed solid mass. By this arrangement a trainee handles a mortar shell which he could not tell apart from a live combat shell.

Referring to the drawings, in which like reference characters refer to like parts throughout the figures, 10 refers generally to a mortar training shell, having a body 12 which in this particular embodiment is a standard 81 mm., HE M362 shell body. The body 12 has an open forward end internally threaded to receive the aft end of a fuze 14. The fuze 14 is completely inert and simulates the standard service fuze in weight and configuration. A standard pull wire 16 is provided and is required to be removed prior to using the shell 10. This operation is the same as that of an actual service round.

The shell is devoid of the common explosive normally used. To compensate for the weight of the explosive, a solid body 18 of appropriate mass is fixed to the rear end portion of the fuze 14. The weight distribution of the body 18 is suitably designed to achieve the required center of gravity of the entire shell 10. Other filler material may be used without departing from the scope of the present invention. However, it has been found, the body 18-fuze 14 arrangement herein is simple and easier to handle than the other types of filler commonly used.

The rearward end portion 20 of the body 12 is closed and externally threaded and adapted to receive the forward end of the fin or tail section 22. This tail section 22 comprises a boom member 24 having fin stabilizers 26 fixed on its rearward end portion. The entire tail section 22 conforms in configuration to that of the standard 81 mm. mortar round. The boom member 24 contains two external cavities, namely a rearward cavity 28, and separated therefrom, a forward cavity 30. The rearward cavity 28 is adapted to receive an ignition or propelling cartridge 32'which when properly initiated provides the propelling force for the shell 10. In this illustration the propelling cartridge 32 is a standard M3 cartridge modified by reducing the propellant powder from grains to 80 grains in order to provide the desired range of yards. As is readily apparent to those skilled in this art the propelling cartridge 32 can be modified to suit a desired application. Whatever the modification may be, however, the propelling cartridge 32 should be capable of being easily inserted into and removed from the cavity 28.

The forward cavity 30 is adapted to slidably receive a smoke generator assembly 34. Furthermore, the cavity 30 is provided with gas discharge means in the form of passageways 36 through the wall of the boom member 24 and into communication with the cavity 30. Two passageways 36 angularly oriented with respect to the longitudinal axis of the shell 10 are illustrated here, but are not limited to this number and/ or orientation. The passageways 36 provide an agress for smoke which will be generated as shown further on in this description.

The smoke generator assembly 34 is clearly shown in FIG. 2, and has an open ended housing 38 having a longitudinal bore 40 therethrough coaxial with the shell 10. The rearward portion of the bore 40 is adapted to receive a rearwardly facing smoke generating cartridge 42. In this illustration the smoke generating cartridge 42 is a standard 2 /2 inch short brass .410 caliber primed shotgun shell in which the shot has been removed and replaced with smoke pellets. The forward portion of the bore is enlarged to receive a firing pin assembly 44 in threaded relationship with the housing 38. The firing pin assembly 44 consists of a hollow holder 46 which comprises a threaded portion 48 extending into the bore 40 and an enlarged portion 50 outside of the forward end of the housing 38. The enlarged portion 50 further defines an axial forward opening 52 therethrough and a flange 54 which axially abuts the end of the housing 38 and radially abuts the wall of the boom member 24 as clearly shown in FIG. 1. At this radial juncture the bore 40 defines an enlargement commencing with a shoulder upon which rests a portion of the rearward face of the flange 54. The combination of the shoulder and flange 54 acts to limit the rearward movement of the housing 38. A firing pin 56 is positioned in the holder 46 and is coaxially oriented with respect to the primer of the smoke cartridge 42. A guide member 58 fixed in the lower end portion of the holder 46 receives the lower end portion of the firing pin stem 60 and functions to guide the striker 62 to the smoke cartridge 42 primer. The stem 60 terminates in a disk 64 which has an outer diameter substantially the same as the inner diameter of the holder. The disk 64 abuts the inner surface of the front end of the holder 46 thereby limiting the forward movement of the firing pin 56. A helical coil spring 66 surrounding the stem 60 is disposed between the forward face of the guide member 58 and the rearward face of the disk 64, and acts to urge a forwardly directed force on the firing pin 56. A finger member 68 extends from the forward face of the disk 64 through the axial opening 52 and, as shown in FIG. 1, abuts a portion of the rearward end of the body 12.

The rearward portion of the housing 38 has a reduced outer diameter which together with the portion of the boom member 24 wall adjacent thereto forms an annular channel 70 between the end of the housing 38 and the passageways 36. This channel 70 provides a path to the passageways 36 for smoke generated by firing the smoke cartridge 42.

In operation, a soldier trainee drops a shell into a suitable mortar launching tube. The propelling cartridge 32 is initiated and provides a force necessary to project the shell 10 over a given trajectory. Upon impact of the shell 10 with the earths surface the smoke generator assembly 34 is caused to slide forwardly compressing the spring 66 thereby bringing smoke cartridge 42 primer in contact with firing pin striker 62. The smoke cartridge 42 is initiated and a cloud of smoke is thereby generated. The smoke passes to the atmosphere via the path provided by the channel and passageways 36. The impact point of the shell 10 is, thus, readily ascertained. The shell 10 is then retrieved, the tail section 22 removed from the body 12, and the spent cartridges 32 and 42 removed and replaced with live ones. When the tail section 22 is returned to the body 12 the shell is ready for reuse.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A mortar training shell comprising a hollow shell body having an open forward end and a closed rearward end;

a fuze member secured to said body forward end;

means in said body for simulating the weight characteristics of an explosive;

a tail section removably fixed to the rearward end of said body, said tail section including a first forwardly open cavity, a second rearwardly open cavity for receiving a propelling cartridge, stabilizing means adjacent said second cavity, and gas discharge means defined by radial passage means in said tail section communicating with said first cavity;

a smoke generator assembly slidably arranged in said first cavity, said assembly including a housing having a rearwardly opening bore communicating with said gas discharge means and receiving a smoke generating cartridge, and firing pin assembly threadedly secured to a forward end of said housing and including a firing pin, a centrally apertured rearward guide slidably receiving said firing pin, and a compression spring normally biasing said pin forwardly away from said guide and smoke generating cartridge and against said shell body rearward end, said guide having rearward protuberance means in engagement with a forward face of said smoke cartridge and normally maintaining said smoke cartridge spaced longitudinally rearward of said firing pin.

2. A mortar training shell as set forth in claim 1 wherein said weight simulating means includes a solid mass secured to the rearward end of said fuze member.

References Cited UNITED STATES PATENTS 2,112,758 3/1938 Blacker lO2-9O X 3,064,577 11/1962 Brandt l0287 X 3,181,465 5/1965 Anthony 102-41 FOREIGN PATENTS 79,384 5/1919 Austria.

SAMUEL FEINBERG, Primary Examiner.

BENJAMIN A. BORCHELT, Examiner.

V. R. PENDEGRASS, Assistant Examiner. 

1. A MORTAR TRAINING SHELL COMPRISING A HOLLOW SHELL BODY HAVING AN OPEN FORWARD END AND A CLOSED REARWARD END; A FUZE MEMBER SECURED TO SAID BODY FORWARD END; MEANS IN SAID BODY FOR SIMULATING THE WEIGHT CHARACTERISTICS OF AN EXPLOSIVE; A TAIL SECTION REMOVABLY FIXED TO THE REARWARD END OF SAID BODY, SAID TAIL SECTION INCLUDING A FIRST FORWARDLY OPEN CAVITY, A SECOND REARWARDLY OPEN CAVITY FOR RECEIVING A PROPELLING CARTRIDGE, STABILIZING MEANS ADJACENT SAID SECOND CAVITY, AND GAS DISCHARGE MEANS DEFINED BY RADIAL PASSAGE MEANS IN SAID TAIL SECTION COMMUNICATING WITH SAID FIRST CAVITY; A SMOKE GENERATOR ASSEMBLY SLIDABLY ARRANGED IN SAID FIRST CAVITY, SAID ASSEMBLY INCLUDING A HOUSING HAVING A REARWARDLY OPENING BORE COMMUNICATING WITH SAID GAS DISCHARGE MEANS AND RECEIVING A SMOKE GENERATING CARTRIDGE, AND FIRING PIN ASSEMBLY THREADEDLY SECURED TO A FORWARD END OF SAID HOUSING AND INCLUDING A FIRING PIN, A CENTRALLY APERTURED REARWARD GUIDE SLIDABLY RECEIVING SAID FIRING PIN, AND A COMPRESSION SPRING NORMALLY BIASING SAID PIN FORWARDLY AWAY FROM SAID GUIDE AND SMOKE GENERATING CARTRIDGE 